Apparatus for making flour



Sept. 18, 1934.

E. M. KlNsLow 1,974,113

APPARATUS FOR MAKING FLOUR Original Filed Sept. l2, 1930 Patented Sept. 18, 1934 nutren srarss 1,974,113 APPARATUS Foie, ivniKiNdv FLoUR Elijah M. Kinslcw, Bars tcw, Calif., assigner,` by

mesne assignments, to Vitimin Milling Corporation, Los Angeles, Calif., a corporation of- Delaware Application September 12, 1930, VSerial No. 481,519 Renewed February 10, 1934 It has been found in practice, in comminuting grain in a buhr mill, that the heat generated between the stones has a deleterious effect upon the constituents of the. grain, resulting in a flour product which is vitally lacking in nutritive value. The action of this frictional heat upon the chemicals, such as phosphorous, potash, lime and silicon, so alters and changes their chemical properties as to destroy their otherwise benecent effect as food products. It is therefore the foremost object of the present invention to provide apparatus whereby the mill and flour products are air-cooled and kept cool during the grinding operation, topreserve, as far as possible, all of the chemical'properties of the grain in their natural state. It is furthermore an object-in addition to air-cooling the mills and productsto carry ofi excessive moisture from the resulting flourproducts, and to do this in such a way that a minimum amount of our is lost in the process.

The subject matter of .this application was dividedout of my application, filed April 18th, 1922, serially numbered 554,897, entitled Method of and apparatus for making cur, which issued as United States Letters Patent No.1,728,18-i, on

September 17th, 1929.

The present invention, as herein disclosed in its preferred speciic embodiment, deals with the apparatus for the milling of flour wherein all of the constituents of the grain are' utilized; although in principle, it need not be limited to such. `In the apparatus, herein shown and described, I use two mills, one in which the Whole grain is first ground, and one in which the tail.- ings from the bolter are reground, after which they are mixed with the products of the first mill so that, except between the bolter and the second mill wherein the unbolted integuments are handled, the whole comminuted products of kthe grain pass through the apparatus in a ccmmingled state. The nutritive value of a flour product of the whole grain is well known andneed not be here further enlarged upon.

The essential details of my apparatus will be more fully disclosed in the following specication, reference being hadto the accompanying drawing for illustrative purposes, in which drawing.-

Fig. 1 is a diagrammatic layout, in sectional elevation, of an apparatus suitable for carrying out the steps of my process; and v Fig. 2 is a fragmentary sectional view through one of the mills illustrating its preferred arrangement. Y

1n the .drawing 1..haveV illustrated apparatus embodying the essential elements" for suitably carrying out the several steps of my process, but it is to be understood that such apparatus need not necessarily be limited to the precise arrangement shown and to be hereinafter described.

The apparatus' comprises essentially two buhr mills, designated by the letters A and B, mounted side by side; having discharge chutes 10 and 11, respectively, discharginginto a blower 12. The blower 12 discharges into the lower end of one side or an elevator 14 -just above the boot, the latter designated bythe nuineral'lS; and this elevator discharges 'as its upper end into a chute l5, which communicates with the upper or receiving end of a bolt 16. The bolt 16 is contained within a bolt housing 17; and the :lines passing through the bolt are deposited in va trough 18, in the bottom o'f the housing 17, and are thence conducted to suitable storage bins (not shown) through themedium' of a screw conveyor 19 operating in and through a discharge chute V20v. The integuments' or coarser' particles failing to pass through the bolt 16 are discharged from its lower end into a'suitable hopper 21, mounted on the upper end of a tube 22; the latter connecting at its discharge end with the mill B.

The air blast produced by the blower 12 is` dissipated by discharging through the side 14a` of the elevator 14 and chute 15, into the bolt casing 17, or'through a suitable tube 23, Vconnected at its lower end to the opposite side 14a of the elevator 14 and at its upper end to a suitable separator 24 mounted upon' the bolt housing Y17. The separator 24 also has lan inlet tube 25 communicatingwith the bolt housing 17, at a point adjacent the discharge end of the bolt 16, and a returnYV chute 26 situated above the bolt 16, and discharging on top of it or beside it intermediate its ends. The buhr mills A and B, are preferably identical and may be of any approved size and design suitable for properly accomplishing' the comminution` of the grain, such as overrunner'or underrunner stones, or of the roller type. For illustrative purposes I showv (in Fig. 2)' a typical one of such mills, of the overrunner type, comprising a pair of buhr stones 27 and 28; 'the'former being' stationary and supported upon a suitable framework 29; lwhile the latter is rotatable on top of the stone 27, and may be driven by any suitabley power through the medium of shafts 30 and 31. A hood 32 is preferably removably'mounted over the upper stone 28; having an upper conical portion 33, terminating ina tube 34. The body portion of the. hood 32 is slightly larger in diameter than the stone 28; and the annular space surform a comparatively air-tight joint. Y also noted here that the hoods 32 are substantially rounding the stone within this hood may be closed at its bottom by a suitable annular plate surntheir upper ends in apertures in the plates 35 intermediate the stones and the hoodso as to t may be air-tight, and form substantially air-:tight coverings for the stones, except for the openings into the chutes 101and 11 and tubes 34. Hoppers 36 are carried by the stones 28, having reduced lower ends 37 extending into the eyes 38 of the stones; their upper ends being of a size to almost but not quite extend to a juncture with the upper conical portions 33 of the hoods 32. Feed pipes 22 Yand 39 extend through the conical tops of the hoods 32 and terminate just above the hoppers 36 to discharge grain and comminuted particles therein, as will be more fully hereinafter explained.

The upper ends of tubes 34 are preferably connected by a common tube 34a leading away from the mills A and B and preferably to the exterior of the building in which they are housed in order that fresh cool air may be supplied to the mills.

The discharge chutes 10 and 11 make air-tight connections at their lower ends with the housing of the blower 12; and the blower may be operated in any suitable manner to draw cool air through tubes 34a and 34, into the hoods 32 and down through the discharge chutes 10 and 11, discharging it into the bottom of the elevator 14. In thus drawing fresh air-preferably from the exterior fj of the building-into the hoods 32, the bulk of it will be drawn down into the hoppers 36 (which are preferably situated directly beneath and concentric with the tubes 34) through the eyes 33 of the stones and out radially between their contiguous grinding surfaces, and thence downwardly through the chutes 10 and 11, and into the elevator 14. Additionally, a proportion of the air drawn into the hoods 32, through the tubes 34, will pass downwardly therein around the tops of y the hoppers 36 to cool the perimeters of the stones 28 and then likewise pass outwardly through the chutes 10 and 11.V The division of the air blast into twostreams is encouraged by the hopper 35 being spaced Vclose to the wallsV of hood 33. In

eiect,- therefore, the hopper serves as a partitionassociated in function with air inlet 34 and blower 12.

After cool air has been thus drawn through the mills A and B and exhausted into the elevator ,jJ 14, it has served its purpose in cooling the mill and the grain being ground, except possibly for its secondary function of carrying off any moisture that may be in the flour product as it is delivered to the elevator 14. After being discharged 1. into the elevator 14 it is necessary to dissipate the force of the blast produced by the blower, and this I do by permitting it to discharge up the housing 14a of the elevator 14, past the endless bucket elevator 14h-and for this purpose the housings 14a are made sufficiently large to admit of the air passage without interfering with its conveyance of the ground products from the bottom thereof, or it may be discharged up the tube 23 and into the separator 24, or through both 'i j of them. The air blast directed up the elevator housings 14a will discharge into the tube 15, connecting with the bolt housing 17, and into the receiving end of the bolt 16. It will thence pass longitudinally through the bolt 16 and impinge 'j against the opposite end 17a of the housing 17,

whence it will be deiiected up the tube 25 and into the separator 24,Y where the flour products will be separated in the usual manner and settle backfinto the bolt housing 17 through the tube 26 and be deposited on top of the bolt 16 intermediate its ends; while the air blast will be exhausted through the tube 40. In discharging up the xtube 23 the blast will travel directly intorthe .separator 24, the air current passing out through the Ytube 40, and the separated flour products returning to the bolt housing 17 through the tube 26, as just described. n

The separator 24 may be of any of the apprbved forms-preferably of the cyclone type-it being only essential to my process thatut be mounted upon the bolt housing 17 in the manner shown, so the separated iiour products will be redeposited in the housingY on top of the bolt 16, or intermediate its ends, and thence in the trough 13 at its bottom and conveyed to the storage bins, as hereinbefore described. In cases where I utilize the elevator housing 14a Yas an erhaust passage for the air blast from the blower 12, I prefer to make the arrangement as illustrated so that the air blast will be carried through the bolt and impinged against the rear wall 17a and thence into the separator, while the return passage from the separator deposits the separated our products in the housing 17 intermediate the ends of the bolt. In this way the air currents passing through the bolt and into the separator will not interfere with the return of the separated flour products into the bolt housing through the tube 26.

In operation the grain is first fed to the mill A through the feed tube 39 from whence it passes, and ils-also drawn, through the chute 10, to the blower 12 and is exhausted into the elevator 14V above the boot 13. The elevator travels in the direction indicated by the arrows and carries the our products from the mill A upwardly and deposits them in the tube 15, which conveys them into the receiving end of the bolt 16. A short screw conveyor 16a on the end of the bolt shaft 16h discharges the flour products from the lower end of the tube 15 into the receiving end of the bolt as indicated by the arrow. The fines passing through the bolts 16 are deposited in the trough 18 in the bottom of the housing 17, and are carried away by the screw conveyor 19 operating in the tube 20, to suitable storage bins. The coarser particles or tailings failing to pass through the bolt 16 are discharged from its lower end into the hopper 21, thence pass through the tube 22, to the mill B, where they are reground and discharged through the chute 11 to the blower 12, from whence they are carried in a comrningled state with the products of mill A, through the mill as hereinbefore described. Thus the rst ground products and the tailings fromV the bolt are always passing through the apparatus in a thoroughly commingled state, except when the tailings are traveling from the discharge end of the bolt through the tube 22 to the mill B, and thence to the blower 12. This method of grinding results in a iiour product of the whole grain, thoroughly ground and chemically uninjured by the action of heat.

During the aforementioned steps the blowel` 12 is drawing cool air through the mills A and B, and exhausting it into the elevator 14. this point the air blast is dissipated up the elevator 14 or through the tube 23, or through both of them. In the case of the former it passes through the tube 15; through the bolt 16, and up the tube 25; into the separator 24, where the From also

flour particles are ser'iaratedY and return to the bolt housing 17 through the tube Y26, while Vthe air passes out through the exhaust tube 40. In the case of the latterthe air blast is dissipated directly up'the tube23 to the separator 24, where the flour is separated and returned to the bolt housing, as described. i f

While I have herein shown and described the preferred specic apparatus for carrying out the several steps of myproc'ess, it is nevertheless to be understood that I doi not wish to 'be limited by the particularapparatus andarrangement shown and described, but that I desire to make any such changes or modifications in arrangement as will properly come within the scope of the appended claims.v -For instance, I may dispense with the use of the tube 23, connecting the elevator 14 and separator 24, and utilize only the elevator housings 14a,` through which to exhaust and dissipate the blast from the blower 12, or may use only the tube 23 for this purpose. The essential object to be accomplished in this connection is to so handle the blast from the blower, after it has accomplished its initial function of cooling the mills, as to exhaust it from the apparatus without its carrying with it any quantity of flour.

Having described my invention, I claim:

l. A milling apparatus comprising a mill hav- A ing upper and nether stones; a material inlet to the mill; an air inlet to the mill; a second mill having upper and nether stones; an air inlet to the second mill; a blower; a discharge chute connecting the first mill and the blower; a discharge chute connecting the second mill and the blower, said air inlets, discharge chutes and blower being arranged to draw cool air through the upper stone and out radially between the grinding surfaces of the upper and nether stones of each mill; a bolt adapted to separate ne particles from tailings; an elevator connecting the discharge end of the blower with the bolt; a housing for the elevator, said housing being adapted to convey air from the blower to the bolt; a tailings discharge connection leading from the bolt to the second mill; a separator; a discharge connection between the blower and the separator; and a discharge connection between the separator and the bolt.

2. A milling apparatus comprising a mill having upper and nether stones; a material inlet to the mill; an air inlet to the mill; a second mill having upper and nether stones; an air inlet to the second mill; a blower; a discharge chute connecting the rst mill and the blower; a discharge chute connecting the second mill and the blower; said air inlets, discharge chutes and blower being arranged to draw cool air through the upper stone and out radially between the grinding surfaces of the upper and nether stones of each mill; a bolt adapted to separate fine particles from tailings; a bolt housing; an elevator connecting the discharge end of the blower with the bolt; a housing for the elevator, said .housing being adapted to convey air from the blower to the bolt; a tailings discharge connection leading from the bolt to the second mill; a separator; a discharge connection between the blower and the separator; and a discharge connection between the separator and the bolt housing.

3. A mill comprising, in combination: an upper stone having an eye therethrough; a nether stone; the two stones having opposed grinding faces; a substantially air-tight jacket encasing the two stones; a A hopper-associated with: the upper stone forming apassage substantially continuous with the upper end of said eye, the'rim of. said hopper andthe interior wall of said jacket being separated :by a relatively narrow clearance; an air inlet in the jacket above the hopper; a materials inlet in the jacket above'the hopper; a discharge outletin the jacket below the hopper; and means to draw astream of air in through the inlet `port and out through the outlet port, said hopger being adapted to divide said stream of air .into one'stream passing around the rim of the hopper and the'periphery Vof the upper stonel and one stream ypassing through said hopper' and through'said eye` of the upper stone and radially cutward between said opposed grinding faces of the two stones.

li. A mill comprising, in combination: an upper stone having an eye therethrough; a nether stone; the two stones having opposed grinding faces; a substantially air-tight jacket having side walls circular in plan encasing the two stones; a round hopper associated with the upper stone forming a passage substantially continuous with the upper end of said eye, the rim of said hopper and the interior wall of said jacket being separated by a relatively narrow annular space; an air inlet in the jacket above ythe hopper positioned to direct a stream of air both through the hopper and through said annular space; a materials inlet in the jacket above the hopper; a discharge outlet in the jacket below the hopper positioned to unite the divided air stream; and means to draw a stream of air in through the inlet port and out through the outlet port. t

5. A mill comprising, in combination: an upper stone having an eye therethrough; a nether stone; the two stones having opposed grinding faces, a substantially air-tight jacket, having a cone-shaped upper portion, encasing the two stones; a conical hopper associated with the upper stone forming a passage substantially continuous with the upper end of said eye, the rim of said hopper and the interior wall of said conical portion of the jacket being separated by a relatively narrow annular space; an air inlet in the jacket above the hopper positioned to force air both through and around the hopper; a materials inlet in the jacket above the hopper; a discharge outlet in the jacket below the hopper; and means to draw a stream of air in through the inlet port and out through the outlet port.

6. A mill comprising, in combination: a revolvable upper stone having an eye therethrough; a nether stone; the two stones having opposed grinding faces; a substantially air-tight jacket having side walls circular in plan encasing the two stones; a conical hopper mounted on the upper stone to revolve therewith and forming a passage substantially continuous with the upper L end of said eye, the rim of said hopper and the interior wall of said jacket being separated by a relatively narrow annular space; an air inlet in the jacket above the hopper positioned to direct air both through and around the hopper and upper stone; a materials inlet in the jacket above the hopper; a discharge outlet in the jacket below the hopper; and means tol draw a stream of air in through the inlet port and out through the outlet port.

7. A mill comprising, in combination: a revolvable upper stone having an eye therethrough; a nether stone; the two stones having opposed grinding faces; a substantially air-tight jacket, having a cone-shaped upper portion, encasing Mil the two stones; a conical hopper' mounted on the upper stone to revolve therewith and forming a passage substantially continuous with the upper end of said eye, the rim of said hopper and the interior wall of said conical portion of the jacket being separated by a relatively narrow annular space; an air inlet in the jacket above the hopper positioned to direct air both through and around the hopper and upper stone; a materials inlet in the jacket above the hopper; a discharge outlet in the jacket below the hopper; and means to draw a stream of air in through the inlet port and out through the outlet port.

8. A milling apparatus comprising: a mill having upper and nether stones; a substantially airtight jacket encasing the two stones; a material inlet in: ytheY jacket above the upper stone; an air inlet in the jacket above the upper stone; a discharge chute extending from the jacket; a blower associated with the discharge chute to draw a stream of air through the mill; and a hopper substantially continuous with the eye of the upper stone forming an air passage to direct air through the eye and out radially between the grinding surfaces of the two stones, said hopper defining, with the jacket, a second air passage directed to the perimeter of Athe upper stone and restricted tooffer sufficient resistance to the air stream to substantially balance the resistance to the air stream offered by the grinding surfaces.

ELIJAH M. KINSLOW. 

